The present invention relates to optical fiber coils in general, and more particularly to a precision-wound optical fiber coil to be used, for istance, for rapid peel deployment of the optical fiber therefrom.
When winding optical fiber onto a bobbin or a similar support, there are several important requirements or conditions that are to be met. First of all, it must be assured that the optical properties of the optical fiber do not suffer as a result of the winding of the optical fiber onto the bobbin, particularly due to microbending losses or other phenomena which deleteriously influence the attenuation characteristic of the optical fiber. On the other hand, it is also important to assure that the optical fiber is wound onto the bobbin in an orderly fashion, that is, that the consecutive convolutions of the coil which are situated in the same layer of the coil are closely adjacent to one another if not in actual contact with each other, and that the convolutions of the next successive layer of the coil are partially received in the interstitial grooves between the convolutions of the preceding layer of the coil. These requirements are seemingly contradictory, inasmuch as it is necessary for the orderly laying of the optical fiber onto the bobbin or on the previously wound layer of the coil to impart a certain amount of tension to the optical fiber during the winding thereof, while this imparted tension results, either alone or in combination with stresses which are caused by differential thermal expansion of the bobbin relative to the coil wound thereon, in a considerable amount of stressing of the underlying layers of the coil by the layers which outwardly overlie the same, this stressing then resulting in deformations of the optical fiber in the underlying layers with attendant deterioration of the optical properties of the optical fiber in such layers, and thus of the optical fiber as a whole. Up to now, the optical fiber coils that have been wound with constant tension have suffered of one or another of the above drawbacks, which resulted in limited acceptance of such coils by the prospective users thereof.